Исходники и презентации

lessons/garbage_collector/add_cleanup/main.go

@@ -0,0 +1,36 @@
+package main
+
+import (
+	"fmt"
+	"os"
+	"runtime"
+	"time"
+)
+
+type FileWrapper struct {
+	file *os.File
+}
+
+func NewFileWrapper(path string) *FileWrapper {
+	file, _ := os.OpenFile(path, os.O_RDONLY|os.O_CREATE, 0666)
+
+	ptr := &FileWrapper{file: file}
+
+	runtime.AddCleanup(ptr, func(f *os.File) { // replace with FileWrapper
+		fmt.Println("Closing file:", f.Name())
+		_ = f.Close()
+	}, ptr.file)
+
+	return ptr
+}
+
+func main() {
+	obj := NewFileWrapper(os.DevNull)
+	_ = obj
+	obj = nil
+
+	runtime.GC()
+	time.Sleep(time.Second)
+
+	fmt.Println("Object is collected by GC")
+}